IC Engines MCQ
IC Engines MCQ includes key topics like SI and CI engines, combustion, fuel systems, thermodynamic cycles, performance parameters, and emissions. These objective questions help students strengthen engine fundamentals for mechanical engineering and competitive exams.
Q1. IC engine stands for?
A. Internal Cooling engine
B. Internal Combustion engine
C. Indirect Combustion engine
D. Inner Compression engine
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Q2. Which cycle is used in petrol engines?
A. Diesel cycle
B. Otto cycle
C. Rankine cycle
D. Brayton cycle
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Q3. Diesel engines work on?
A. Carnot cycle
B. Diesel cycle
C. Otto cycle
D. Stirling cycle
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Q4. The ignition in diesel engines is due to?
A. Spark
B. Glow plug
C. Compression
D. Battery
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Q5. The stoichiometric air–fuel ratio for petrol is?
A. 5:1
B. 8:1
C. 14.7:1
D. 20:1
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Q6. In IC engine, scavenging means?
A. Burning
B. Exhaust gas removal
C. Cooling
D. Oil filtration
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Q7. Compression ratio of petrol engine is?
A. 6–10
B. 14–20
C. 1–3
D. 20–25
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Q8. Compression ratio of diesel engine is?
A. 4–6
B. 6–10
C. 14–22
D. 25–30
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Q9. Which component stores lubricating oil?
A. Radiator
B. Sump
C. Crank
D. Carburetor
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Q10. Which part converts reciprocating motion to rotary motion?
A. Piston
B. Connecting rod
C. Crankshaft
D. Camshaft
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Q11. The function of a carburetor is to?
A. Ignite fuel
B. Mix air and fuel
C. Compress air
D. Reduce noise
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Q13. Octane number indicates?
A. Fuel viscosity
B. Fuel knocking resistance
C. Density
D. Flash point
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Q14. Cetane number indicates?
A. Diesel ignition quality
B. Antifreeze strength
C. Viscosity
D. Density
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Q15. Knocking occurs due to?
A. Late combustion
B. Early combustion
C. Uncontrolled combustion
D. Low temperature
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Q16. The spark plug is used in?
A. Diesel engine
B. Petrol engine
C. Steam engine
D. Gas turbine
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Q17. The function of a governor is?
A. Control temperature
B. Control speed
C. Control fuel grade
D. Control lubrication
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Q18. Turbocharger increases?
A. Fuel
B. Air supply
C. Oil pressure
D. Noise
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Q19. Supercharging improves?
A. Cooling
B. Power output
C. Lubrication
D. Ignition
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Q20. Pre-ignition happens due to?
A. Hot spots
B. Poor lubrication
C. Lean mixture
D. Used oil
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Q21. Which of the following is a two-stroke engine part?
A. Valves
B. Ports
C. Camshaft
D. Pushrod
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Q22. Power stroke occurs when?
A. Piston moves down
B. Piston moves up
C. Piston stops
D. Engine stops
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Q23. Volumetric efficiency is?
A. Actual/Ideal volume of air
B. Heat/Work
C. Fuel/Air ratio
D. Pressure/Volume
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Q24. Air–fuel ratio in diesel engine is?
A. Constant
B. Variable
C. Equal to petrol
D. Not required
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Q25. Crankcase ventilation removes?
A. Oil
B. Fuel
C. Blow-by gases
D. Coolant
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Q26. Cooling system in IC engine prevents?
A. Fuel injection
B. Overheating
C. Lubrication
D. Ignition
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Q27. The ideal efficiency of Diesel cycle depends on?
A. Cut-off ratio
B. Compression ratio
C. Both A and B
D. Temperature
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Q28. The fuel injector is used in?
A. Petrol engine
B. Steam engine
C. Diesel engine
D. Gas turbine
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Q30. Catalytic converter reduces?
A. HC, CO, NOx
B. Only CO2
C. Only soot
D. Only oxygen
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